Today, we mess up encryption application in two primary ways. We either try to create our own (always a bad idea) or misconfigure protocols to use weak algorithms (also a bad idea, but it's surprisingly easy to do).
With respect to the first way we screw up encryption, we need to be a bit more detailed with respect to what we mean. When I say "create our own", I don't mean "try to create our own encryption algorithm". I mean, nobody's going to do this. Not that nobody can, after all the initials in RSA stand for real folks, but that it's likely that you don't know anybody who can do this. And that you don't know anybody who knows anybody who can do this. And for the most part we all realize this, so we don't try. Go us!